1. Field of the Invention
The present invention generally relates to a cable connector type transceiver module having module connectors from whose backside a cable for balanced transmission is extended and is used to connect a HDD (hard disk drive) to a switching device in a RAID (redundant array of independent disks).
2. Description of the Related Art
FIG. 1 is a block diagram showing a RAID. As shown in FIG. 1, plural HDDs 20 and a switching device 30 are disposed in a RAID 10, and each HDD 20 is electrically connected to the switching device 30 so that data can be transmitted and received between the HDD 20 and the switching device 30. Plural RAIDs 10 are disposed and each RAID 10 is connected to a server 40 via a network by Ethernet (registered trademark).
FIG. 2 is a diagram showing a connection between the HDD 20 and the switching device 30. Since the distance between the HDD 20 and the switching device 30 is as small as one to two meters, conventionally, as shown in FIG. 2, the connection between them is performed by electric transceiver modules 50 and 60 and a cable connector 70 which uses a copper wire cable 71, instead of by an optical fiber.
The electric transceiver module 50 has a thin and long rectangular parallelepiped shape and provides a control IC package 51, a card edge section 52 at one end, a connector 53 at the other end, and has a function to receive/transmit data. Similarly, the electric transceiver module 60 has a thin and long rectangular parallelepiped shape and provides a control IC package 61, a card edge section 62 at one end, a connector 63 at the other end, and has a function to receive/transmit data.
The cable connector 70 provides the copper wire cable 71 and connectors 72 and 73 one at each end.
The electric transceiver module 50 is inserted into a slot 21 of the HDD 20 and the card edge section 52 is connected to a card edge connector 22 of the HDD 20.
The electric transceiver module 60 is inserted into a slot 31 of the switching device 30 and the card edge section 62 is connected to a card edge connector 32 of the switching device 30.
The connector 72 is connected to the connector 53 and the connector 73 is connected to the connector 63.
The transmission rate of data between the HDD 20 and the switching device 30 is approximately 2 Gbps.
[Patent Document 1] Japanese Laid-Open Patent Application No. 2000-68007
In a next generation RAID, the transmission rate of data between the HDD 20 and the switching device 30 becomes, for example, 4 Gbps or more. That is, the transmission rate becomes high speed. When data are transmitted at high speed, losses of signals in a transmission line become large.
In the transmission line between the HDD 20 and the switching device 30, the losses occur at the connection point between the connector 72 and the connector 53, the connection point between the connector 73 and the connector 63, and entire long wiring patterns on printed circuit boards in the electric transceiver modules 50 and 60.
Consequently, in the above connection between the HDD 20 and the switching device 30, the losses of signals become large at the transmission rate of 4 Gbps, and the transmission rate of 4 Gbps cannot be efficiently utilized.